ngx_pagespeed is an open-source
Nginx module created by Google to help Make the Web Faster by
rewriting web pages to reduce latency and bandwidth.

PageSpeed Filter Examples

Here are some of the most useful PageSpeed filters. Each one has
a simple HTML example attached; click "before" to see the
original file, and "after" to see what PageSpeed produces
with that filter (and only that filter) enabled. The two
versions should look exactly the same, but the "after" one will
be (slightly) speedier. Use "view source" to see
the PageSpeed difference!